Furnaces



April 24, 1962 B. R. ANKERSEN FURNACES 2 Sheets-Sheet 1 Filed May 4, 1959 NTA.

Aprll 24, 1962 B. R. ANKERSEN 3,031,176

FURNACES Filed May 4, 1959 2 Sheets-Sheet 2 lNvEN-roR Borge Richard Ankersen if@ www 'faq/W57,

34131376 FURNACES Borge Richard Anlrersen, Broomall, Pa, (32h71 Chatham Lane, Birmingham, Mich.) Filed May 4, 1959, Ser. No. 810,662 6 Claims. (Cl. 263-33) This invention relates to furnaces and, particularly, to a rotary barrel furnace.

Furnaces for the heating of billets, forging blanks forgings and the like have been heretofore made in various forms. One of the problems in heating such materials is the problem of raising the articles to an elevated temperature without, at the same time, unduly oxidizing and corroding the surfaces. In the past, this has been accomplished by the use of salt baths and the like and by the use of expensive, often inefficient closed protective atmosphere furnaces. I have invented a furnace which makes it possible to continuously heat or heat treat billets, forging blanks, forgings and the like at high temperatures Without causing any significant oxidation or corrosion on the surfaces of the articles being treated. Preferably, I provide an outer cylindrical housing adapted to be rotated about its axis, an inner heat resistant lining on the inner periphery of said housing, means for heating the housing at one point in its rotation, a trough like conveyor passing through said housing, means for introducing a protective fluid into said trough intermediate the top and bottom thereof, and conveyor means adapted to carry the articles to be heated through said trough in said protective iluid.

Preferably, the protective fluid is introduced into the bottom of the trough in the form of low pressure combustible gas. Preferably, the heating means is arranged to direct the llame against the inner lining at the bottom of its point of travel to a temperature which will cause ignition of the combustible fluid in the trough around the work being heated. The conveyor means may be any well known conventional mechanism such as a rocker hearth, a pusher mechanism, etc.

In the foregoing general description, I have set out certain objects, purposes and advantages of my invention. Other objects, purposes and advantages will be apparent from a consideration of the following description and the accompanying drawings, in which:

FIGURE l is a vertical section through the axis of a furnace according to my invention; and

FIGURE 2 is a vertical section on the line II--II of FIGURE l.

FIGURE 3 is an end elevation of FIGURE l, viewed from the left.

Referring to the drawings, I have illustrated an outer cylindrical shell or housing provided with supporting ribs 11 spaced about and extending around the entire periphery. The supporting ribs 1.1 ride on spaced rollers 12 journalled on shafts 13 in supporting frames 14 on base 15. A refractory lining 16 is provided within the shell or housing 10, an inner formed refractory liner 17 is fixed on the liner 16 and is provided with axially inwardly projecting portions 17a. The foregoing shell and lining forms a cylindrical barrel rotatable about its axis on rollers 12. A refractory front wall 18 is provided to close one end of the housing 10. A second end wall 19 is provided at the opposite end of housing 1G to close said opposite end. An axially extending hearth member 20 is connected'with end wall 19 and extends through the interior of the barrel and through an opening 13a in end wall 18 generally axially of the housing 10. The hearth member 26 is provided with a gas inlet manifold 21 and burners 22 directed downwardly from the bottom of the hearth member against the inner lining 17 of the barrel. The hearth member is formed so as to extend 3,@3Ll7b Patented Apr. 24, 1962 diametrically across the axis of the housing llt) to be almost in contact with the ends of the projections 17a of the inner refractory lining thereby forming a seal between the bottom portion of the barrel and the top portion of the barrel. The end wall 19 is provided with an annular recess 23 which extends upwardly around the hearth member and connects to an integral ilue 2d. The upper portion of the hearth member is provided with a U or channel-shaped hearth or passage 25 through which articles to be treated may be passed. Spaced above the bottom 25a of the channel-shaped hearth on the sidewalls 25h thereof, intermediate top and bottom, are gas inlets Z6 which are connected to mains 26a passing through the interior of the hearth member, low pressure gas is delivered through the openings 26 to form a gaseous atmosphere about the work passing along hearth 25. This gas is ignited at its surfaces and the work is heated by the reflected heat from the refractory lining 17 as it moves about its axis. Preferably, the hearth member 20 is made of refractory material 27 supported upon a framework Z3 which is in turn supported on trunnions 29 pivoted in a conventional saddle bearing 29a on standards 30 to form a rocker hearth which may be driven in any conventional manner for example a horizontal arm dit may be attached to the I-beams 20a which carry the hearth. A crank arm 41 pivoted to the end of the arm 4h, on a shaft ft2, may be connected to an ecccn` tric shaft 43 on a drive wheel 44, driven by an extension of a shaft 13, through a gear reducer 45. This is a conventional type of drive, well-known in the mechanical arts.

The operation of the furnace herein described is as follows.

The rollers 12 are driven in the usual manner by anV electric motor. This rotation is imparted to the shell or housing 10 through ribs 11 causing the barrel to rotate" about its axis. Heat from the burners 22 is directed downwardly (see FIGURE 2) onto refractory lining 17.

Gases from combustion pass to annular recess 23 and out through flue 24. As the barrel rotates this heated inner lining comes to the top of the furnace (see FIG- URE 2), radiant heat is thereupon directed onto the hearth 25 and onto any work passing therealong. At the same time, the work is surrounded by low pressure gas being fed through openings 26. This gas is caused to ignite and forms a protective hot, non-oxidizing atmosphere about the work. The products of combustion of this low pressure gas in the hearth 2S together with unburned gas are carried toward flue 24 and are mingled with the oxygen rich products of combustion from recess 23. These unburned gases are then burned and form a preheat zone on the base of the llue about the articles entering hearth 25 for treatment.

It will be obvious that various types of refractory linings may be used for the inner lining 17 and that the surfaces of the lining may take various conligurations other than that shown. It is desirable, however, to have a configuration which will form a side seal with the hearth member and which will give the maximum radiant surface.

It is also evident that other uids than combustible gas may be fed through inlets 26. For example, nitrogen or an inert gas may be used to form a protective cover over the work which is radiantly heated.

While I have illustrated and described a present preferred embodiment of my invention, it will be understood that the invention may be otherwise variously embodied within the scope of the following claims.

I claim:

1. A furnace structure comprising an outer rotatable housing, drive means rotating said housing, an inner heat resistant lining in said housing, conveyor means passing through said housing and generally dening a separate heating area and a treating area in said housing, said conveyor means adapted for carrying work through the said housing in the treating area to receive radiant heat from the lining, means for heating the lining in said separate heating area during rotation, and means for introducing a protective atmosphere about the work during its travel through the furnace.

2. A furnace structure comprising an outer rotatable housing, drive means rotating said housing, an inner heat resistant lining in said housing, a trough like conveyor means passing through said housing and generally dening a separate heating area and a treating area in said housing, said conveyor means adapted for carrying Work through the said housing in the treating area to receive radiant heat from the lining, means for heating the lining in the heating zone, means for introducing a protective atmosphere in said conveyor about the work and means continuously carrying the Work through the conveyor.

3. A furnace structure comprising an outer rotatable housing, rotatable about a xed axis, drive means rotating said housing, an inner heat resistant lining in said housing, a hearth member extending axially of said housing dividing the housing into a heating zone and a separate treating zone, and carrying burner means directing a arne onto the lining over a fraction of the surface thereof in the heating zone, conveyor means passing through said housing adjacent the hearth means and adapted for carrying work through said housing to receive radiant heat from the lining in the treating zone, and means for introducing a protective atmosphere about the work during its travel through the furnace.

4. A furnace structure comprising an outer rotatable housing, drive means rotating said housing, an inner heat resistant lining in said housing, a hearth member dividing the interior of said housing into separate heating and treating zones, burner means on the hearth means directing a flame onto the lining over a fraction of the surface thereof in the heating zone, conveyor means adjacent the hearth member adapted for carrying Work through said d housing to receive radiant heat from the lining at a point spaced from the point of heating in the treating Zone, and means for introducing a combustible Huid onto the conveyor about the work during its travel through the furnace.

5. A furnace structure comprising an outer rotatable housing, drive means rotating said housing, an inner heat resistant lining in said housing, axially extending divider means forming separate heating and treating Zones Within said housing, means for heating the lining in the heating zone, a trough like conveyor passing through said housing in the treating zone adapted to carry work through the housing to receive radiant heat from the lining at a point spaced from the point of heating and means for introducing a protective atmosphere in said conveyor about the Work.

6. A furnace structure comprising an outer rotatable housing, drive means rotating said housing, an inner heat resistant lining in said housing, axially extending divider means forming separate heating and treating zones Within said housing, means for heating the housing lining in the heating zone, a trough like conveyor passing through said housing in the treating zone adapted to carry Work through the housing to receive radiant heat from the lining in the treating zone at a point spaced from the point of heating, means for introducing a combustible fluid atmosphere in said conveyor about the work, means continuously urging the work through the conveyor and means exhausting the products of combustion from the heating and treating zones.

References Cited in the tile of this patent UNITED STATES PATENTS 789,371 Laxton May 9, 1905 890,250 Thompson June 9, 1908 1,280,889 Spang Oct. 8, 1918 1,474,705 Bluemel Nov. 20, 1923 2,497,125 Hulrne Feb. 14, 1950 2,621,160 Johnson et al. Dec. 9, 1952 

